Are decisions using cost-utility analyses robust to choice of SF-36/SF-12 preference-based algorithm?

Health Qual Life Outcomes. 2005 Mar 4:3:11. doi: 10.1186/1477-7525-3-11.

Abstract

Background: Cost utility analysis (CUA) using SF-36/SF-12 data has been facilitated by the development of several preference-based algorithms. The purpose of this study was to illustrate how decision-making could be affected by the choice of preference-based algorithms for the SF-36 and SF-12, and provide some guidance on selecting an appropriate algorithm.

Methods: Two sets of data were used: (1) a clinical trial of adult asthma patients; and (2) a longitudinal study of post-stroke patients. Incremental costs were assumed to be 2000 dollars per year over standard treatment, and QALY gains realized over a 1-year period. Ten published algorithms were identified, denoted by first author: Brazier (SF-36), Brazier (SF-12), Shmueli, Fryback, Lundberg, Nichol, Franks (3 algorithms), and Lawrence. Incremental cost-utility ratios (ICURs) for each algorithm, stated in dollars per quality-adjusted life year (dollars/QALY), were ranked and compared between datasets.

Results: In the asthma patients, estimated ICURs ranged from Lawrence's SF-12 algorithm at 30,769 dollars/QALY (95% CI: 26,316 to 36,697) to Brazier's SF-36 algorithm at 63,492 dollars/QALY (95% CI: 48,780 to 83,333). ICURs for the stroke cohort varied slightly more dramatically. The MEPS-based algorithm by Franks et al. provided the lowest ICUR at 27,972 dollars/QALY (95% CI: 20,942 to 41,667). The Fryback and Shmueli algorithms provided ICURs that were greater than 50,000 dollars/QALY and did not have confidence intervals that overlapped with most of the other algorithms. The ICUR-based ranking of algorithms was strongly correlated between the asthma and stroke datasets (r = 0.60).

Conclusion: SF-36/SF-12 preference-based algorithms produced a wide range of ICURs that could potentially lead to different reimbursement decisions. Brazier's SF-36 and SF-12 algorithms have a strong methodological and theoretical basis and tended to generate relatively higher ICUR estimates, considerations that support a preference for these algorithms over the alternatives. The "second-generation" algorithms developed from scores mapped from other indirect preference-based measures tended to generate lower ICURs that would promote greater adoption of new technology. There remains a need for an SF-36/SF-12 preference-based algorithm based on the US general population that has strong theoretical and methodological foundations.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Algorithms*
  • Asthma / economics
  • Asthma / physiopathology
  • Clinical Trials as Topic
  • Cost-Benefit Analysis / methods*
  • Decision Trees*
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Outcome Assessment, Health Care / economics
  • Outcome Assessment, Health Care / methods*
  • Patient Satisfaction
  • Psychometrics
  • Quality-Adjusted Life Years*
  • Sickness Impact Profile*
  • Stroke / economics
  • Stroke / physiopathology
  • United States